How Much Gas Does an Instant Hot Water System Use?

Instant hot water systems, also known as tankless water heaters, are becoming the go-to choice for households and businesses across Australia. But one of the most common questions homeowners ask is: How much gas does an instant hot water system use?

In this blog, we will look into the factors that affect gas usage in gas instant water heaters and help you make an informed decision about whether this system is the right fit for you.

What Is an Instant Gas Hot Water System?

Before we delve into gas usage, let’s start by understanding how an instant gas hot water system works. Unlike traditional hot water systems that store water in a tank and heat it continuously, instantaneous hot water systems heat water on demand. When you turn on a hot water tap, cold water passes through the system, where it is heated by a gas burner before being delivered to your tap.

This on-demand heating process means that there is no need to store hot water in a tank. As a result, instantaneous systems are far more energy-efficient than their traditional counterparts, which constantly burn gas to maintain a tank of hot water. They only use gas when there’s a demand for hot water, significantly reducing gas consumption and eliminating heat loss that happens in storage systems.

How Much Gas Does Hot Water Use?

The amount of gas used by an instantaneous gas hot water system depends on several factors. Let’s break these down:

1. Flow Rate

Flow rate refers to how much water the system can heat and deliver per minute. Most instantaneous hot water systems have a flow rate between 12 to 27 litres per minute. The higher the flow rate, the more gas will be required to heat the water. If your household requires a higher flow rate (for example, if you have multiple bathrooms), your gas consumption will increase accordingly.

2. Temperature Rise

The temperature rise is the difference between the incoming water temperature and the desired hot water temperature. In cooler climates, where the incoming water temperature is lower, the system will use more gas to raise the water to your desired temperature. On the other hand, in warmer areas, less gas will be required.
For example, if the incoming water temperature is 10°C and you want your hot water to be at 50°C, the system will need to work harder and use more gas than if the incoming water is already at 25°C.

3. Water Usage Patterns

The more frequently hot water is used, the more gas will be consumed. A larger family with higher hot water demands will likely use more gas than a small household. If you’re running the shower for longer periods or using hot water for tasks like washing dishes, the system will consume more gas to keep the water heated.

4. System Size and Efficiency

Modern instantaneous gas hot water systems are available in various sizes to accommodate different household or business needs. Larger systems with higher flow rates use more gas, especially if they are designed to provide hot water for multiple outlets simultaneously. Selecting the right system size for your specific requirements is essential to balance efficiency and gas consumption, ensuring you have sufficient hot water without excessive energy use.

How Much Does Gas Hot Water Cost Per Month?

On average, instantaneous gas hot water systems use between 0.5 to 1.5 gigajoules (GJ) of gas per day, depending on factors such as household size, water usage, and system efficiency. Over a month, this could translate into an average gas cost of $50 to $120. However, this is highly variable depending on the individual circumstances of your home.

For example, a family of four with moderate hot water use could expect to pay around $75 per month for gas to power their hot water system. In contrast, a smaller household with minimal hot water demand might only pay $40 to $50 per month.

Benefits of Instantaneous Gas Hot Water Systems

1. Energy Efficiency

As mentioned briefly above, instantaneous hot water systems are far more energy-efficient than traditional storage tank systems. Because they only heat water when it’s needed, they avoid the energy wastage that happens when a tank system continually heats and reheats stored water. This efficiency translates into significant savings on your energy bills, especially over time.

2. Space-Saving Design

Unlike traditional water heaters that require large storage tanks, instantaneous systems are compact and can be installed on the wall. This is ideal for homes with limited space, such as apartments or smaller homes. Even larger systems designed for multiple outlets maintain the space-saving advantages.

3. Lower Carbon Footprint

Because instantaneous gas hot water systems use less energy, they also produce fewer emissions. By reducing your gas usage, you’re contributing to a smaller environmental footprint, which is an important consideration for many homeowners looking to reduce their impact on the planet.

How Long Do Instant Gas Hot Water Systems Last?

Instantaneous gas hot water systems have a long lifespan, often lasting between 15 to 20 years with proper maintenance. This is significantly longer than traditional systems, which typically only last 10 to 12 years.

The lack of a storage tank means there’s less chance of rust or corrosion, which can shorten the lifespan of tank-based systems. With regular servicing and maintenance, such as checking the gas connections and cleaning the heat exchanger, you can ensure that your system continues to function efficiently for many years.

LPG Gas Hot Water Systems: A Viable Alternative

LPG (liquefied petroleum gas) instantaneous hot water systems offer the same benefits as natural gas-powered systems but are ideal for properties that do not have access to a natural gas supply. These systems are commonly used in rural or off-the-grid locations. LPG hot water heater operates in much the same way as natural gas systems, delivering efficient on-demand hot water and reducing overall energy costs.

LPG vs. Natural Gas

• Fuel Source: LPG is stored in liquid form in pressurised tanks or cylinders, while natural gas is delivered directly through underground pipelines.
• Cost: LPG tends to be more expensive due to the transport and refilling of tanks, whereas natural gas is cheaper because it is supplied directly through pipelines.
• Energy Efficiency: Both LPG and natural gas are energy-efficient, but natural gas tends to be more efficient in the long term. This is because natural gas is delivered directly through pipelines, ensuring a continuous supply.

Conclusion

Instantaneous gas hot water systems are a highly efficient and cost-effective solution for modern properties in Australia. By choosing the right system and maintaining it well, you can enjoy reliable, on-demand hot water for many years to come.

To learn more, call Fix N Flow today at 1300 319 275, or fill out our online form for a consultation.